Floodgate, Dredging Plans Unveiled

At one of the first large public meetings since Covid began, several hundred people crowded into the Kingwood Community Center last night. They came to see the City unveil floodgate and dredging plans for Lake Houston. Stephen Costello, PE, the City’s Chief Recovery Officer, addressed dredging. And Chris Mueller, PhD, PE, of engineering firm Black & Veatch discussed adding more floodgates to the Lake Houston Dam. Mayor Pro Tem Dave Martin coordinated the meeting.

To see both presentations, click here. Or see the summaries below.

Dredging: About Half Done

In late 2019, the Army Corps finished hydraulic dredging in the area south of the West Fork mouth bar. Then in early 2020, the City of Houston began mechanical dredging to extend the effort. In terms of the estimated dollars designated for dredging, the effort is about halfway done.

The first four rows on this chart are done or almost done. They total $114 million out of a projected total of $222 million.

The last two rows on the chart above are estimates because they depend on bids currently in progress and a long-range plan not yet complete. The need for a long-term plan and maintenance dredging were identified early on by the Army Corps so that any benefits of dredging were not immediately wiped out by future sedimentation.

Scope of Long-Range Dredging Plan Still in Development

A long-range dredging plan for Lake Houston is critical. We must understand where the sediment comes from, how fast it builds up, where it builds up, and the consequences of not removing it periodically.

The numbered dots in the photo above show channels south of the East and West Forks draining into Lake Houston where sediment can also build up.

Costello says the City is currently working with affected homeowner associations to discuss cost-sharing arrangements.

He also says that the City must identify a long-range site for depositing the spoils that is suitable for hydraulic dredging. He called the mechanical dredging now in progress “not sustainable.” Currently, the City is using Berry Madden’s property on the West Fork south of Kingwood’s River Grove Park to deposit the mechanical dredging spoils. That’s a long haul for barges on the East Fork.

Next Dredging Steps: Channel to East Fork and East Fork Itself

Contractors must next deepen the channel between the West and East Forks of the San Jacinto to move dredging equipment and spoils back and forth (see below).

Current location of dredging is near yellow dot.

From there, dredgers will move slightly north of where Luce Bayou (far right) enters the East Fork and begin dredging the East Fork mouth bar. See large circle above. The map shows that area grew shallower by up to nine feet between 2011 and 2018. Imelda, in September 2019, made it grow even shallower. Note the fresh deposits of sand in the photo below now poking up above the water.

Growth of East Fork Mouth Bar after Imelda in September 2019. Photo taken in November 2019.

Additional Floodgates for Lake Houston Dam

Chris Mueller of Black & Veatch then discussed the reasons for adding additional floodgates to Lake Houston, preliminary engineering findings, and an implementation schedule.

The primary objective: to increase the outflow capacity of the dam to reduce the risk of future flooding. However, he emphasized that reducing the risk for people upstream of the dam cannot have an adverse impact on people below it. See below.

He emphasized that Lake Houston is, first and foremost, a drinking water reservoir. He also emphasized that the dam is almost seventy years old and near the end of its useful life. Significant safety issues exist in working with such old concrete.

Calculating the Benefit/Cost Ratio of Additional Floodgates

Mueller then explained how FEMA calculates the benefit/cost ratio of additional floodgates.

  • On the benefit side, it considers: the reduction in water surface level; how many buildings and streets that will prevent from flooding; reduced societal impacts; and reduced impacts to business revenues. These are primarily damage costs avoided.
  • On the cost side of the equation, FEMA factors in construction costs and annual operation and maintenance costs.

To win project approval, the City must show that the benefits of additional floodgates exceed the costs in a 100-year storm, similar to Imelda. Such a storm elevates the lake 10 feet.

The peak inflow to Lake Houston in a 100-year storm: 286,000 cubic feet per second (CFS), enough to fill the Astrodome in 3 minutes! However, during Harvey, SJRA estimated the peak inflow at 400,000 cfs.

Proposed Alternative Produces 11-Inch Benefit Nearest Dam

A hydrologic and hydraulic analysis conducted by Black & Veatch will help prove up the benefit/cost analysis. The San Jacinto Watershed (including Buffalo Bayou) includes flow from eight counties.

In evaluating about ten alternatives for adding floodgates, Black & Veatch considered both cost and non-cost factors listed below.

The company’s first choice was to install additional gates on the earthen portion of the dam on the east side. But environmental considerations there would have delayed the project by a decade or more.

So they decided to recommend a 1,000 feet of crest gates on the west side of the spillway instead. See example of crest gates in operation below.

An air bladder near a bottom hinge raises or lowers the floodgates to let water in/out

Such gates would increase the discharge capacity to 45,000 cfs, more than four times the current capacity of 10,000 cfs. That’s still only about a third of the discharge capacity of the floodgates on Lake Conroe. But according to Martin, that would still be enough to lower the level of the lake 4 feet in 24 hours.

However, before floodgate construction can begin, engineers must evaluate:

  • Downstream impacts and how to mitigate them
  • Impact to the stability of the existing concrete dam

Back in the 1950s when the Lake Houston dam was built, engineers did not use rebar. So this will be a delicate operation. Contractors must cut 6 feet into the existing spillway; cap the remaining concrete with a slab; and install the crest gates on top of the slab.

Black & Veatch must also develop an operations protocol for new floodgates that maximizes upstream benefits and limits downstream impacts. Mueller shared this schedule with attendees.

Best-Case Project Timeline Shows Completion in 2024

Schedule as of 7/8/2021. Detailed engineering could take another year.

A best-case scenario shows construction starting at the end of 2022 and finishing before the start of hurricane season in 2024. So, at least three more hurricane seasons to get through before seeing any benefit from additional gates.

Posted by Bob Rehak on 7/9/2021

1410 Days since Hurricane Harvey

To Reduce Future Flooding, We Need to Focus on BOTH Mitigation AND Root Causes

After writing about flooding daily for nearly four years, I have developed some beliefs about how to reduce future flooding. In the last 20+ years, Harris County has spent more than $2.6 billion on flood mitigation. And I know one engineer who claims it could take another $50-60 billion to fix all of the County’s flooding problems. That raises the question, “Why aren’t we focusing more on preventing them in the first place?”

Changing Landscape of Flood Mitigation

Flood-mitigation projects alone can’t prevent future flooding because the landscape constantly changes. As population density increases, so does housing density, impervious cover, and runoff. As areas build out and land prices escalate, people often build homes in places they shouldn’t (floodways and floodplains). That puts others at risk. But the allure of having a water view, dazzles potential buyers who may not understand the risk of future flooding.

When neighborhoods flood, community groups demand action. Someone commissions an engineering study. Years later, the engineers quote an often astronomical cost for flood-mitigation projects. Finding the money can take years longer. Or lead to a frustrating dead end and repeat flooding.

Unwitting Flood Victim: A Personal Story

I once bought a new house on Spring Creek in a Dallas suburb. The home was supposed to be two feet above the hundred-year floodplain. It looked out over the Richardson golf course. My wife and I were ecstatic…until pickup trucks started floating down the creek on minor rains.

I managed to get a three-city commission started to look into the causes. The City Engineers from Garland, Richardson and Plano petitioned the Army Corps to re-survey the creek. They found that…

Instead of being 2 feet above the hundred-year floodplain, we were now 10 feet below it.

They pointed to Plano upstream from us. It was the fastest growing city in America at the time. They also pointed to the development of an 80-acre shopping mall just upstream from us.

With two small babies at the time, we decided that the beauty of the location no longer justified the risk. We put the home on the market, disclosed the flood problems, took a $35,000 hit on the sale (about 20% of the purchase price in those days), and moved to (please don’t laugh) Houston!

Urban Sprawl Increases Future Flood Risk For People in Center

Houston has grown even faster than Dallas. We are now completing the third ring of highways around the City. Just as development of areas around Beltway 8 contributed to flooding woes inside Loop 610, now, the Grand Parkway will contribute to flooding woes farther out.

Grand Parkway extension in Liberty County, photographed May 26, 2019. A magnet for future development.

Look Outward, Not Just Inward, to Reduce Future Flooding

This continued expansion demands that we look outward, not just inward to reduce future flooding. The counties around Harris have an opportunity now encourage development practices that respect the property rights of others. Those include, but are not limited to:

  • Preservation of green space and wetlands, nature’s sponges.
  • Adequately sized detention and retention ponds
  • Lining channels with grass to reduce erosion and sediment deposition downstream
  • Control of housing density
  • Use of green technologies in home building

If every new home and development “retained its rain,” no one downstream would face increased flood risk.

The mantra of floodplain managers

But, alas, that costs money. And for every ten thousand dollars that you increase the price of a home, you also price X number of people out of the market. Not just the home buying market, but the Houston market.

Cost of Land Can Be 40% of New Home’s Cost

According to one homebuilder, land now accounts for 40% of the cost of a new home. So, we constantly see pushback from developers who hire engineers willing to find a way to make questionable projects happen. And that’s how we get places like Colony Ridge – a development that didn’t exist 10 years ago that is now larger than any city in Liberty County – built on wetlands.

A small part of the Colony Ridge expansion now underway. Photo taken at end of June, 2021.

Ironically, Colony Ridge is just upstream from Luce Bayou which has received the least flood-mitigation funding since 2000.

Pay Now or Pay Later

Harris County Flood Control Capital Improvement Spending since 2000.

The Colony Ridge expansion area above will drain into Luce which runs through Huffman downstream. One can only guess how long it take for flooding to strike there and how long it will take to find a solution now that a developer has permanently altered the landscape and destroying even more wetlands.

Sensible regulation and enforcement could reduce future flooding risk at no cost to the public. But upstream county commissioners are eager to experience the financial freedom that a larger tax base will bring. And their residents aren’t eager to pay for someone else’s flood mitigation.

And that is why fighting future flooding will always be a two-front war.

Posted by Bob Rehak on 7/8/2021

1409 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Baseless Claims of Historic Racism, White Supremacy in Allocation of Flood Funds

Members of the Northeast Action Collective (NAC) have falsely alleged “historic racism” in the allocation of flood-mitigation funds. And without evidence, the group also cited “a rising white supremacist movement” in Harris County as a reason to move money from high-income to low-income watersheds “as quickly as possible.”

Analysis of historical funding data obtained from Harris County via a Freedom of Information Act (FOIA) Request shows that minority and low-income watersheds have received the lion’s share of funds since 2000. Yet at the 6/29/21 Harris County Commissioners Court meeting, NAC members claimed the opposite.

From Baseless to Bizarre

“Historic racism” and “white supremacy” were just two of dozens of baseless and bizarre claims in the group’s manifesto.

NAC also claimed that:

  • It is “fighting for better drains and more regular drain upkeep.” NAC then blames the Harris County Flood Control District (HCFCD) for being insensitive to residents needs. Perhaps that’s because HCFCD is not responsible for street drainage; the City and (in unincorporated areas of Harris County) Precinct Commissioners are.
  • “The City won’t pay attention to neighborhoods where Black and Brown people live” … even as they complained to County Commissioners.
  • HCFCD has “underfunded” Greens and Halls Bayous for decades while ignoring the fact that the entire county was underfunded before the 2018 flood bond.
  • HCFCD needs more transparency, even though NAC ignored readily available information about HCFCD spending.
  • The flood bond was supposed to counteract historic racism, even though the language approved by voters never mentions race.

These claims deserve closer scrutiny. Let’s look at some of the most serious falsehoods.

Racial Equity Not in Flood-Bond Language

NAC claims the flood-bond promised racial equity in the distribution of funds; it didn’t. The text of the flood bond never mentions race, minorities, historic underinvestment, income, social justice, social vulnerability or any of the other things NAC says it does. Those concepts were all heaped onto the one mention of “equitable” in the bond language (paragraph 14G). It puts equity in a geographic context with a prefatory clause focused on political boundaries. (“Since flooding issues do not respect jurisdictional or political boundaries, the Commissioners Court shall provide a process for the equitable distribution of funds…).

Areas, such as Lake Houston, asked to include that because flood mitigation requires upstream detention in other counties. The inability to cross political boundaries for flood mitigation would handicap areas near the county line forever.

Historic Racism Not Evident in Funding

NAC claims “historic racism” in flood mitigation funding, but refuses to acknowledge historic advantages in funding:

  • Eight minority and low-income watersheds (out of 23 total) received 71% of all HCFCD capital funds between 2000 and Harvey. ($1.1 billion out of $1.5 billion.) The other 15 higher income watersheds split the remaining $400 million. So “historic racism” in funding does not exist, at least not in Harris County and not at HCFCD. See links to data and related articles below.
  • Out of 23 watersheds, Halls and Greens Bayou Watersheds alone received $222 million between 2000 and Harvey. That’s 15% of all funding during those years.
  • They also received another $200 million out of $1.1 billion spent since Harvey – 18%.
HCFCD Capital-Improvement Spending between 2000 and Harvey arranged by percentage of low-to-moderate income (LMI) residents. Halls has the highest LMI % and Little Cypress the lowest. The top eight watersheds (darker blue) have LMI percentages above 50%; the others below. Data obtained via FOIA request.
New detention basin at Hopper and US59, photographed in April. One of four new basins in the Halls Bayou watershed that doesn’t exist according to NAC.

“Rising White Supremacist Movement” Not Seen in Funding or Evidence

NAC claims, “The most viable path to equity is to reallocate money for projects in wealthier watersheds to projects in watersheds with predominantly BIPOC and LMI residents.” (BI-POC stands for Black, Indigenous and People of Color. LMI stands for Low-to-Moderate Income.) But NAC doesn’t stop there.

Because of “a rising white supremacist movement in Texas and the county, and decades of underinvestment, the only strategy rooted in justice is to move as much money as quickly as possible to low-income watersheds.”

Northeast Action Coalition

Then NAC claims that its members do not believe that “current HCFCD leadership is actually committed to racial equity or justice.” I guess they don’t get out in the neighborhood much and look at all the flood-mitigation projects going in!

One of three new detention basins under construction in the Greens Bayou Watershed. It doesn’t exist either according to NAC.

Demand for Transparency That Already Exists

The NAC manifesto also demands, “full transparency on spending.” Yet:

  • HCFCD supplied historical funding data going back more than two decades. NAC and partner organizations ignored it.
  • All HCFCD spending is audited.
  • HCFCD’s website details spending and projects in each watershed.
  • It also shows – by watershed – all active construction and maintenance projects, and their value.
  • All HCFCD expenditures are approved by Commissioners in open, public meetings.

When Commissioners Ellis and Garcia claim that all the funding is going to rich watersheds and none to poor watersheds, they should know better. They approved all the money going to low-income areas!

The Real Problem

In the 18 years between 2000 and Harvey, the Flood Control District had only $1.5 billion to spend on capital improvement projects. Even with partner funding, that works out to only a little more than $80 million per year. According to multiple sources, for decades HCFCD had to save up money – sometimes for years – to afford construction projects. So, in some years, there were NO flood-mitigation projects at all, anywhere in the county.

Despite that, eight LMI watersheds received $1.1 billion out of $1.5 billion total dollars. That’s 71% of all capital spending – hardly “historic racism” or evidence of “white supremacy.” The other 15 more affluent watersheds combined got only 29%.

The sad fact is that no one in Harris County got enough flood-control dollars to prevent flooding before Harvey. It took Harvey to wake voters up to the need for better flood control.

In fairness, as I have shown in related articles below, minority, low-income watersheds did suffer a disproportionate share of damage in the last two decades. But dollars have flowed to that damage. Those damaged communities have received the vast majority of flood-mitigation funds.

Halls and Greens didn’t flood because of racism. And shouting racism from the rooftops won’t fix their flooding problems. It will only cloud issues and divide people.

For More Information

In early March, I submitted a FOIA request to Harris County for capital improvement funds by watershed dating back to 2000. Here is the county’s response: HCFCDs historical construction funding by watershed.

I then compiled a summary spreadsheet that includes related information, such as population and watershed size, also supplied by the County in response to my FOIA request.

After analysis, I published these findings:

Also, here are several articles with aerial photos that show what the money bought.

Finally, here’s an article about how Commissioner’s filled a potential shortfall in partnership funds to prevent possible delays in construction of flood mitigation projects. Trust To Fully Fund Flood Mitigation Projects Without Partner Assistance For At Least Next Six Years.

Posted by Bob Rehak on July 7, 2021

1408 Days after Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Reminder: Floodgate Meeting at Kingwood Community Center on Thursday, July 8

On Thursday, July 8, Mayor Pro Tem Dave Martin will host a pubic meeting to discuss the status of adding more floodgates to the Lake Houston Dam. Preliminary engineering finished earlier this year. In March, the Coastal Water Authority board approved Black & Veatch to begin final engineering.

Need for More Gates

The Lake Houston Area Task Force identified more and higher capacity floodgates as a key element in the area’s flood-mitigation strategy. The current gates have one-fifteenth the capacity of those at the Lake Conroe Dam. That makes it difficult to shed water from Lake Houston before people flood if Lake Conroe opens its gates as it did during Harvey.

During Harvey, Conroe released 79,000 cubic feet per second. That was one third of all the water coming down the West Fork between Humble and Kingwood. All by itself, that 79,000 CFS would have been the ninth largest flood in West Fork history. And that made the difference between flooding and not flooding for thousands of homes and businesses near the lake.

During Harvey, the peak flow over the spillway was five times the average flow over Niagra Falls. A wall of water 11 feet tall cascaded over the spillway above. Enough to fill NRG stadium in 3.5 minutes.

Lake Houston Dam During Harvey. The proposed crest gates would go in the far upper left of the spillway.

Floodgate Meeting Details

See the meeting details below.

Thursday, July 8, 2021
At the Kingwood Community Center (4102 Rustic Woods)
Doors Open 5:30 PM
Dredging Update Starts 5:45 PM
Gate Update Starts at 6 PM

Chief Recovery Officer, Stephen Costello, will provide a very brief update on Lake Houston Dredging operations at 5:45 p.m. before the Spillway Improvement Project program begins.

The program to discuss the Lake Houston Dam Spillway Improvement Project will start at 6:00 p.m. and conclude at 7:45 p.m. But don’t worry about sitting through a 2 hour meeting.

The main presentation by Black & Veatch, the project engineers, will be followed by a short Q&A session. The meeting will then transition into breakout sessions. Breakout tables will let residents engage with project management staff and engineers in small groups to ask more detailed questions.

Project Benefits

The Lake Houston Dam Spillway project will increase the outflow capacity of the Lake Houston Dam. The project proposes installing new crest gates in the existing uncontrolled spillway. This will allow for a rapid decrease of water levels in Lake Houston in advance of storm events to prevent or reduce upstream flooding. Engineers estimate the recommended alternative could help about 35,000 residents and 5,000 structures. It’s important for people to understand that if they flooded from streams or channels far from the lake during Harvey, this may not help them.

Funding

A Federal Emergency Management Agency (FEMA) Hazard Mitigation Grant Program provides $4.3 million for engineering and positions the city to receive another $42.7 million for construction.

Posted by Bob Rehak on 7/6/2021 based on info provided by Dave Martin’s Office

1407 Days since Hurricane Harvey

Progress Report on New Flood Maps and Flood-Insurance-Risk Ratings

On June 29, 2021, Harris County Flood Control District (HCFCD) gave Commissioners an update on the progress of new flood maps and flood-insurance-risk ratings. The flood-map changes could become effective as early as late 2023. FEMA’s new Risk Rating 2.0 system for flood-insurance pricing will be phased in during the next few years. See details below.

MAAPnext About Half Complete

MAAPnext is Harris County’s Modeling, Assessment and Awareness Project. The purpose: to develop the next generation of flood maps and tools. It will provide a better assessment of flood risks for individual properties, and make the nature of those risks easier for property owners to understand.

One of the significant changes: the new maps will capture different types of flooding, such as street flooding. This is currently the biggest missing piece of the flood-risk rating picture, according to the MAAPnext project team.

The new maps will also come with individual property reports that estimate flood depth, water-surface elevations, annual-chance of flooding grids, and 30-year chance of flooding grids. That last will estimate your chance of flooding at least once during a 30-year mortgage. The flood map grids will also be more detailed. They will provide estimates down to the 3 ft X 3 ft level.

FEMA and Harris County expect to have:

  • Draft flood-risk maps and associated data available for public review by the end of this year.
  • Preliminary Flood Insurance Rate Maps (FIRMs) for release by next summer.
  • Public meetings to review and explain the FIRMs to officials and residents during the second half of next year.

The earliest likely date that the new rate maps could become effective: late 2023.

Changes to flood-insurance premiums as a result of map changes could only happen after the new maps become effective.

Understanding FEMA’s Risk Rating 2.0

Risk Rating 2.0 is a massive FEMA effort to put the National Flood Insurance Program (NFIP) on a sound actuarial footing.

FEMA is updating the National Flood Insurance Program‘s (NFIP) risk rating methodology through the implementation of a new pricing methodology called Risk Rating 2.0. The methodology leverages industry best practices and cutting-edge technology to enable FEMA to deliver rates that are actuarily sound, equitable, easier to understand and better reflect a property’s flood risk.

More Risk Factors Considered

Elevations, flood-hazard zones, and rating tables will no longer be the only metrics used in calculating the flood-insurance premium for a property. For example, premiums will be distributed across all policyholders based on home values and a property’s unique flood risk. FEMA will also consider flood frequency, multiple flood types—river overflow, storm surge, coastal erosion and heavy rainfall—and distance to a water source along with property characteristics such as elevation and the cost to rebuild.

More Equitable Rates

Currently, many policyholders with lower-value homes are paying more than they should and policyholders with higher-value homes are paying less than they should.

That said, FEMA expects 87% of single-family homes to see a flood-insurance-premium increase of about $120 per year. Another 4% could see an increase of about $121 to $360 per year. Finally, 9% could see a decrease of up to $1,200 per year.

Source: FEMA Fact Sheet – County-Level Premium Change Analysis reproduced in HCFCD document

Phased Implementation

Beginning October 1 this year:

  • New policy holders will be subject to the new rates.
  • Current policy holders eligible for renewal can take advantage of premium decreases.

Starting in April 2022:

  • Existing policy holders who expect an increase with the new method could renew under Risk Rating 2.0, but will have an option to keep their current policies if cheaper for up to two years.
  • All remaining policies renewing on or after April 1, 2022, will be subject to the new rating methodology.  

Contact your flood insurance agent to clarify all timing, rate and discount questions.

How Does MAAPnext Factor into Risk Rating 2.0?

Harris County Flood Control District in partnership with FEMA lead the MAAPnext effort to revise flood insurance rate maps. FEMA alone leads the Risk Rating 2.0 effort to calculate new flood insurance rates. The maps will help calculate new premiums.

For more information, visit the MAAPnext website or the Risk Rating 2.0 section of FEMA’s.

Posted by Bob Rehak on July 4, 2021 based on information from HCFCD and FEMA

1405 Days since Hurricane Harvey

Preliminary Engineering Contracts Approved for Two Kingwood Drainage Improvements

On June 29, 2021, Harris County Commissioners approved two contracts for preliminary engineering on Taylor Gully and the Kingwood Diversion Ditch. The Taylor Gully project includes looking at Woodridge Village in Montgomery County to possibly expand detention-pond capacity there. See more below.

Taylor Gully Project

Harris County Flood Control District (HCFCD) awarded Idcus, Inc. a $180,555 preliminary engineering contract to develop up to five conceptual alternative scenarios for modifying Taylor Gully. HCFCD and Idcus will then select three scenarios for more detailed analysis. Idcus must perform the work within 300 days of the Notice to Proceed.

The alternative modeling scenarios may include:

  1. Preferred Channel Alternative: This would look at improving the slope, width and lining of channel in conjunction with the existing detention on the Woodridge Village site. This purpose: to determine if the existing detention and proposed channel improvements suffice to mitigate flooding.
  2. Expanded Detention: This would look at expanding the existing stormwater detention on the Woodridge Village site so that no channel improvements are necessary.
  3. Alternative Channel/Detention: This would look at a combination of the two scenarios above. It would determine the amount of additional detention and channel improvements necessary to ensure no adverse impact all the way to Lake Houston.
  4. Optimization Alternative: Building on the alternatives above, this effort would examine additional alternatives to produce a no-adverse-impact solution while maximizing the flood mitigation and minimizing construction costs.
Deliverables for the alternatives include:
  • Channel and basin layouts
  • Estimates of benefits for various levels of storms (100-year, etc.)
  • Right-of-way requirements
  • Cost estimates for right-of-way acquisition, engineering and construction management.
  • Performance metrics, i.e., estimated acreage of land inundation, number of structures in floodplain, number of structures flooded and miles of inundated roadway.
  • A scoring matrix to rank the alternatives.

The scope also includes, when necessary:

  • Hydrologic and hydraulic analysis
  • Surveying
  • Soil sampling
  • Environmental site assessment
  • Subsurface utility exploration
  • Landscape architecture

Finally, Idcus will hold two public engagement meetings near the beginning and end of the project and consult with community groups such as KSA.

Geographic scope includes the Woodridge Village property in MoCo plus the Taylor Gully channel in Harris County.

Kingwood Diversion Ditch

HCFCD entered into a contract with Neel-Schaffer, Inc. for $437,685 for preliminary engineering on the Kingwood Diversion Ditch. Within 300 days,Neel-Schaffer must:

  • Evaluate existing site conditions, previous studies, other projects that could affect this one, topography, rights-of-way, utilities, and soil surveys.
  • Evaluate existing bridges
  • Conduct and H&H analysis to assess existing and proposed conditions (from 2-year to 500-year storms).
  • Analyze Channel Improvements including the:
    • Impact of TIRZ #10’s latest design to replace the Northpark Bridge
    • Diversion structure at the confluence of Bens Branch and the Diversion Channel
    • Drop structures in lieu of a concrete lined channel to minimize high velocities due to the steep grade between
      Walnut Lane and Deer Ridge Estates Blvd.
  • Develop phased construction plans based on available funding, potential impacts and benefits.
  • Conduct two public engagement meetings and coordinate with community groups.

HCFCD may also require Neel-Schaffer to provide addition services when necessary, such as:

  • Surveys
  • Geotechnical investigations, i.e., bridge borings
  • Environmental assessment
  • “Jurisdictional” determination. Does this channel fall under the jurisdiction of the Army Corps? If so, channel design may need to be altered.
  • Determination of detention pond requirements
  • Exploration for subsurface utilities
  • Obtaining permits from the Corps
  • Providing Landscape Architect services
Extent of Kingwood Diversion Ditch. It runs from the new St. Martha Catholic Church north of Northpark to the fire station on Kingwood Drive. Then it runs down to Deer Ridge Park where it makes a turn and enters the West Fork at River Grove Park.

For Complete Text of Contracts…

The first half of each link below contains contract details such as compensation. The second half contains the scope of work.

They were items 146 and 147 respectively on the agenda for the 6/29/21 Commissioner’s Court meeting.

Next Steps

In general, the critical path for each of these projects will follow the project-lifecycle pattern of all HCFCD projects.

Typical steps for new projects constructed under the 2018 bond program.

HCFCD will:

  • Conduct public meeting
  • Develop, review and prioritize alternative designs
  • Commissioner’s court reviews and votes on recommendation
  • Move to final design of selected alternative with same company
  • Engineering company develops construction specs
  • Bid
  • Award
  • Build

These were two of many such contracts approved in the last Commissioners Court meeting.

Both came out of the Kingwood Drainage analysis. More on projects affecting other parts of the Lake Houston Area in future posts.

Posted by Bob Rehak on 7/3/2021

1404 Days after Hurricane Harvey

Precinct 4 Transforming Mercer to Increase Flood Resilience

New amenities – including a grand entryway, boardwalks, and water features – will transform Mercer Botanic Gardens over the next decade as part of a plan to expand the gardens and make them more flood resilient.

Mercer approved its master plan, designed by Halff Associates Inc., in 2019, after buying more than 47 neighboring acres outside the special flood hazard area.

Mercer’s New Master Plan designed for Harris County Precinct 4 by Halff Associates.

Phase 1 of Transformation Already Underway

Phase 1 of the plan began March 8 and will take six months to complete. Improvements include building three greenhouses on higher ground to replace the Central Garden greenhouses. The extra elevation is expected to keep nursery plants safe from high water and provide a staging area for staff and equipment during disasters like Hurricane Harvey, which caused catastrophic damage at the botanic gardens.

“We decided we couldn’t just rebuild, because we would always be in harm’s way,” said Chris Ludwig, Mercer’s director. “The best option was to move our greenhouses to higher ground and make the facilities that couldn’t be moved more flood resilient.”

New and Improved Amenities on More Acreage

Before building the greenhouses, crews will excavate part of the property to create a detention area, using the excess soil to raise the property above Hurricane Harvey’s flood line. Plans also include demolishing the Central Garden greenhouses and using the space as an open lawn area for events and family-friendly outdoor movies.

Storey Lake and the Creekside Ramble were closed in 2016 after sustaining significant flood damage. But both have re-opened and will eventually link to other planned amenities.

Most development will occur over the next decade on a 47.44-acre plot adjacent to Mercer. Amenities include:

  • Three greenhouses
  • Water features
  • Trails
  • Observation greenhouse for exotic plants
  • Water wall
  • Amphitheater.

A boardwalk will span the pond, leading visitors past a Japanese Garden to a ziggurat – a tall earthen tower resembling the structure at McGovern Centennial Gardens, near the Houston Zoo. A twisting pathway will lead to the top of the tower so visitors can view Mercer from above. The boardwalk will also provide a shortcut to Storey Lake and a new rookery and water feature.

Baldwin Boettcher Library, which has been closed since Hurricane Harvey, will reopen as Mercer’s entrance. Additionally, Precinct 4 will restore Mercer’s Botanical Information Center, also damaged during Harvey, and open it to Baldwin Boettcher staff for library programs and classes.

Mercer’s west side, which remains mostly undeveloped, may also see a few improvements and new amenities over the years, including a Reflective Garden, Tree Village, and Maple Mall. A restroom and garden space is expected to open at the front of the westside parking area in fall 2021. Property also has been set aside on both sides of Mercer for connections to the Cypress Creek Greenway.

Inspire Your Family to Love Nature

Mercer is located in Humble at 22306 Aldine Westfield Road at Cypress Creek. That’s a little more than a mile north of FM1960. If you want to inspire your family to love nature, this is a great place to visit. And so convenient!

Click to view the master plan in a high resolution PDF format.

Posted by Bob Rehak on 7/2/2021 based on a press release and presentation by Harris County Precinct 4

1403 Days since Hurricane Harvey

Elsa Upgraded to Hurricane

A USAF mission into Elsa along with radar data and surface observations from Barbados indicate that Elsa is now a hurricane. However, uncertainty remains about the storm’s track and intensification.

Elsa in the center of the image is skirting the northern coast of South America and about to cross over the windward islands. Note the small core near the center.

Just yesterday, the NHC showed Elsa remaining a tropical storm all the way to Florida. Now, the National Hurricane Center shows hurricane conditions are quickly spreading into the Windward Islands. Various watches and warnings are in effect for portions of the Caribbean Islands (See graphic below).

86 MPH Winds Reported

According to Jeff Lindner, Harris County’s meteorologist, Elsa has taken advantage of favorable conditions in the last 24 hours. Both the Air Force and land observers reported sustained winds of 86mph this morning. That makes Elsa a hurricane. Radar indicates good banding features and a small, central core.

Elsa continues to race WNW near 30mph which is extremely fast for a hurricane.

However, the system has thus far kept its low- and upper-level centers aligned.

Track

A strong sub-tropical ridge of high pressure to the north of the hurricane, will influence the track for the next 48 hours. Then Elsa will approach a weakness in the ridge and the forecasts become more uncertain.

One model shows the storm nearly dissipating over the Dominican Republic by Sunday. However, others show Elsa turning more north. Increasingly, this appears to be the more likely outcome. However, the spread is very large from east of the Bahamas to near the northern Yucatan at days 4-5 so confidence remains lower than average on the track.

Two models show Elsa making a beeline toward the central Gulf, but most take it east.

Intensity

Conditions seem favorable for increasing development. But the fast forward motion of Elsa could become a negative factor. Models show a large spread in intensity guidance, but most keep Elsa near the intensity it is now. As it approaches the Gulf, it should be a strong tropical storm or weak hurricane, but some forecasters see it growing much stronger.

NHC continues to lean toward the lower end of the guidance spectrum, but continues to indicate that Elsa could become stronger than forecasted – especially over the NW Caribbean Sea early next week.

Keep one eye on the Gulf. For the latest updates, check the National Hurricane Center.

Posted by Bob Rehak on 7/2/2021 at 8:30 am based on information from the NHC and HCFCD

1403 Days since Hurricane Harvey

Harris County Creates Trust To Fully Fund Flood Mitigation Projects Without Partner Assistance For At Least Next Six Years

On Tuesday, 6/29/21, Harris County commissioners voted unanimously to shift Harris County Toll Road Authority and other county funds into a trust designed to help bridge potential shortfalls in partnership funding. The amount would be $40 million per year. As a result, construction of Flood Bond Projects can continue without interruption or delay for at least the next six years. If more partnership funding materializes during that time, funds deposited in the trust could help cover non-bond projects farther into the future.

The issue of a potential shortfall in bond funding boiled into headlines back in March. Precinct One Commissioner Rodney Ellis demanded to know where the money would come from to finish construction projects in Halls and Brays Bayou Watersheds if partnership funds did not materialize as planned. He gave Budget Management and the Flood Control District three months to develop a plan for backstop funding.

As of June 2021, HCFCD Needed to Find Additional $951 Million

When considering all flood-bond projects – not just those in Halls and Greens watersheds – the situation looks like this as of the end of June. See explanation of chart below.

As of 6/28/21, without any additional partnership funding, the potential need could be $951 million.

In 2018, voters approved a $2.5 billion flood bond that included $5 billion worth of projects (first column). Part of the $2.5 billion voters approved (third column) was designed to help attract another $2.5 billion in partnership funding. But only $1.25 billion has materialized so far (fourth column). With other transfers already made (fifth, sixth and seventh columns), that leaves a need of $951 million.

Commissioners wanted to know where that money could come from. Especially after HCFCD received nothing in a statewide competition for $1.1 billion in US Department of Housing and Urban Development (HUD) hazard mitigation funds. General Land Office Commissioner Bush later requested a direct allocation of $750 million for Harris County, but that could take years – if it comes.

Trust Not a Substitute for Partnership Funding

The county intends to step up the search for partner funding. But if that funding does not materialize, it has also created a Flood Resilience Trust. The Trust would:

  • Backstop the 2018 Bond Program
  • Mitigate risks of increased construction costs
  • Potentially fund future flood risk reduction projects beyond the 2018 Bond Program

The Trust does not eliminate the need for partner funding. If partner funds materialize as hoped, HCFCD can use any excess money in the trust to construct future flood mitigation projects beyond the bond program.

The graphic below shows that $489 million has already been identified and allocated to the trust from various sources. The new element added on Tuesday (column six) includes $343 million in HCTRA funds. With rounding and other funds, that would help create a proposed Flood Resilience trust of $833 million to help cover the $951 need.

$40 Million Transfer Per Year from Toll Road Funds

Approximately $40 million per year would be transferred into the trust (red line in chart below). That should cover any unsecured spending through about 2027. By then, hopefully, HCFCD will have identified more partnership funds.

Commissioners spent a considerable amount of time debating the legality of transferring toll road funds to flood mitigation projects. The consensus: toll road development has impacted flooding in Harris County. Flood Control identified a $15 billion need to mitigate increased stormwater runoff caused by historical development of roadways. So, it should not be hard to find a transportation connection to most flood control projects that would satisfy auditors.

Equity Prioritization Framework Will Apply to Trust

The pie chart below shows the weights that will be given to various factors when deciding which projects to develop first with the additional funds.

Weighting in new prioritization framework

This differs slightly from the original equity prioritization framework. Compare the table below.

Weighting in 2019 Equity Prioritization Framework

They seem substantially similar, but the names of some factors have changed. For instance:

  • “Cost per structure” has replaced “project efficiency.”
  • “Flooding Frequency” has replaced “Existing Conditions/Drainage Level of Service.”
  • “Structures Benefitted” has replaced “Flood Risk Reduction.”

Cost per structure is not home value. It is the cost of the project divided by the number of homes benefitted.

“Structures Benefitted” counts the number of structures only, not the the value of those structures.

Thus, this factor gives more weight to densely developed urban areas.

Commissioners Ellis and Garcia have complained bitterly and repeatedly that FEMA Benefit/Cost Ratios for flood mitigation projects include a weighting factor for home value that theoretically gives higher preference to affluent neighborhoods. But that’s only one of many factors that FEMA considers.

This report from William & Mary’s law school explains that “impoverished communities may receive a Federal cost share of up to 90 percent of the total amount approved under the Federal award to implement eligible approved activities in accordance with the Stafford Act, but these communities must meet stringent criteria to receive funding.”

Regardless, I see no weight given to more valuable homes in Harris County’s prioritization guidelines. In fact, the density factor and social vulnerability combine for 45% of a project’s total score.

The biggest problem with this framework is that it doesn’t differentiate between street flooding and bayou flooding. Additional flood control projects for the bayous may not help homes that flood due to water collecting in streets.

For More Information

Here’s the full presentation made by the Flood Control District’s new acting director, Alan Black. And here’s a high-level summary prepared by the Harris County Budget Management Department.

Posted by Bob Rehak on 7/1/2021 based on information provided by Harris County Flood Control and Budget Management departments

1402 Days after Hurricane Harvey

Tropical Depression 5 Becomes Tropical Storm Elsa Overnight

In its 5 a.m. Thursday update of the Atlantic Basin, the National Hurricane Center upgraded tropical depression 5 to Tropical Storm Elsa.

Elsa is the earliest-known fifth named storm on record for the Atlantic basin in the satellite era (1966-present), breaking the record formerly held by Edouard on July 6, 2020.

Notice the beginning of an eye in Elsa at the 5 o’clock position and slight rotation.

Eastern Gulf Probabilities

At 5 a.m. Thursday 7/1/2021, forecasters believe that the eastern Gulf has up to a 30% chance of experiencing tropical-storm-force winds by late this week or early next.

The tropical cyclone’s cloud pattern became a little better organized overnight. Convective banding features are becoming more evident over the western and southwestern portions of the circulation.

Upper-level outflow is well-defined to the west of the system, and restricted over the eastern semicircle. The current intensity is 35 knots, making the cyclone a tropical storm.

The storm has been accelerating westward overnight, and the initial motion is around 22 knots. A strong subtropical ridge should steer the system quickly to the west-northwest for the next 3 days or so. However, there is significant uncertainty in the track forecast from days 3-5.

Disagreement Among Models, High Uncertainty

The ECMWF model turns the cyclone northward after interacting with Hispaniola while the other models such as the GFS, HWRF, and U.K. Met take Elsa across western Cuba and into the southeastern Gulf of Mexico. The official forecast is similar to the previous one last night. However the discrepancy in the models makes confidence in this track lower than usual.

Some intensification is likely for the next day or two, since Elsa is expected to be in an environment of warm sea-surface temperatures, fairly low vertical wind shear, and high mid-level relative humidity.

However, potential interaction of Elsa with the mountainous land masses of the Greater Antilles later in the forecast period could disrupt the circulation somewhat. Therefore the official intensity forecast, like the previous one, is quite conservative.

Key Messages

  1. Tropical storm conditions are expected beginning early Friday in portions of the Windward and southern Leeward Islands.
  2. Heavy rainfall from the system will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible.
  3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week. Interests in these areas should monitor the system’s progress and updates to the forecast.
  4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast.

There is no forecast threat to the Houston area. Just beware in case you are traveling in the Caribbean or to Florida this week or next.

Posted by Bob Rehak at 6am on 7/1/2021 based on NHC information

1402 Days since Hurricane Harvey